/Engine/Source/Runtime/Engine/Public/Animation/AnimInstanceProxy.h
Get local weight of any montages this slot node is playing. If this slot is not currently playing a montage, it will return 0. This is double buffered, will return last frame data if called from Update or Evaluate.
float GetSlotMontageLocalWeight ( const [FName](API\Runtime\Core\UObject\FName) & SlotNodeName ) const